Posts Tagged ‘freezing embryos’

Early-stage Thawed Frozen Embryos Lead to Fewer Miscarriages

Most IVF clinics have embraced freezing embryos as a way to enhance a couple’s chances of achieving a pregnancy.

Better ovulation induction protocols now allow the harvesting of 10 or more mature eggs from a woman from one cycle of hormonal stimulation.

Freezing embryos allows couples to have several IVF treatment cycles from the same egg collection, reducing the number of times that the ovaries are stimulated and, therefore, reducing the costs.

The most costly part of an IVF cycle is the ovulation induction, egg retrieval, and fertilization stages.

Frozen embryos can also be used during a natural cycle IVF without any hormonal stimulation.

Natural cycle replacement is an easier procedure, and is usually recommended for a woman who ovulates regularly and normally.

Thawed Embryo Transfer

The thawed embryos are placed into the uterus three to five days after ovulation in exactly the same way as fresh embryos.

The transfer is timed to the stage of development of the embryo.

Embryos frozen at the 8-cell stage are transferred earlier than those frozen at the blastocyst stage.

For a natural cycle, the fertility team will thaw earlier embryos one day after ovulation (two days after the LH peak) and make the transfer on the day of the thaw.

Blastocysts are thawed five days after the LH peak and transferred on the day of the thaw.

About 75% of frozen embryos survive the thawing at Weill Cornell in New York, says Zev Rosenwaks, MD, director and physician-in-chief of the Center for Reproductive Medicine at the Weill Cornell Medical Center.

“Our pregnancy rates are slightly higher – more than 50% – when blastocysts are thawed and transferred compared to earlier stage embryos.”

A new study in the December issue of Reproductive BioMedicine Online (www.rbmonline.com) states that miscarriage is less likely to occur after the transfer of fresh embryos compared with frozen-thawed embryos, but also that the age of the embryos at the time of freezing could influence the miscarriage rate.

The retrospective analysis of more than 52,000 clinical pregnancies recorded on the Australian and New Zealand Assisted Reproduction Database between 2004 and 2008 showed that a woman’s age and obstetric history are closely related to the risk of miscarriage, but that the transfer of fresh embryos is associated with fewer miscarriages than transfer of frozen–thawed embryos.

Transferring thawed embryos at an earlier stage of development than the blastocyst stage reduced the likelihood of miscarriage, leading the authors to suggest that transferring fresh blastocysts and freezing of cleavage-stage embryos might reduce miscarriage rates.

However, a retrospective analysis of large national databases is mainly useful to identify trends and generate hypothesis.

“It is interesting that miscarriage rates of frozen blastocysts were higher in the Australian study, particularly since it is well known that blastocysts have a lower frequency of chromosomal anomalies than cleaved embryos,” said Dr. Jacques Cohen, senior editor of Reproductive BioMedicine Online, of the study.

“Blastocyst culture is still a relatively new approach and culture-related factors such as selection for freezing at blastocyst stage may have affected early learning experiences in some clinics.

It is therefore important to repeat a similar analysis of Australian clinic data during subsequent years.”

Frozen Embryos Healthier

Initially, there were some concerns about the health of children born to women who had frozen embryos transfers, but now we know these children are just as normal as those conceived with fresh embryos.

There’s even some evidence that frozen embryos are healthier than fresh embryos.

A Danish study found that women implanted with frozen embryos had babies who weighed slightly more than those implanted with fresh embryos, and they also had fewer multiple births.

The reason for the differences is probably that only top-quality embryos survive the freezing and thawing process, allowing the selection of healthier embryos.

Fertility Options Move Beyond Sperm and Embryo Banks

Cancer treatments such as chemotherapy and radiation can cause a woman to experience premature menopause and diminish her chance of getting pregnant. Similarly, chemotherapy, radiotherapy, or radical pelvic surgery can reduce a man’s ability to produce sperm.

In fact, 140,000 men and women younger than 45 years old face a cancer diagnosis each year.

But all is not lost for those who suffer from infertility caused by cancer treatments. Many survive treatment and are still young enough to have children.

There are ways to preserve a woman’s fertility, including freezing embryos, freezing her eggs, or freezing tissue from her ovaries before she goes for cancer treatment.

In the first and most effective method, a woman can undergo an IVF stimulation cycle, and the retrieved eggs can be fertilized with her partner’s or donor sperm.

The newly created embryos are then frozen with the anticipation that she will have the embryos replaced back to her uterus when she is cured.

That’s just what Ewelina and Dominic Saputo did.

Ewelina received a leukemia diagnosis when she was 23, and she and her then finance went through the process to create and freeze embryos, according to a recent Detroit Free Press article.

Six years later, the young couple from Sterling Heights, MI, just north of Detroit, went through an IVF procedure, and they now have twin, 10-month-old boys, Julian and Antonio.

For men, sperm collected before cancer treatment can be saved for many years.

World-renowned cyclist Lance Armstrong became a father for the fourth time after his sperm were preserved before his treatment for testicular cancer.

One of the innovative techniques available to men is to obtain tissue samples with a tiny needle and then use them to fertilize an egg stored for later use, which is called testicular sperm extraction.

The newspaper article includes a nice chart of simple or minimally invasive techniques available or coming soon to leading fertility programs for both men and women.

If you receive a cancer diagnosis, ask your oncologist how you can preserve your fertility.

New IVF techniques have taken fertility preservation to a whole new level.